Pulverizer



p l 21, A. .1. BRIGGS 7 1,801,842

PULVERI ZER Filed Aug. 8, 1925 '3 Sheets-Sheet l ATTORNEY A. JrsRle cas 1,301,842

April 21, 19311 PULVERIZER 3 SHeets-Shet 2 Filed Aug. 8 1925 INVENTOR 4%0/ ffl/ ATTORNEY .um MM 1 II I I? April 21, 1931. r -A J, BRIGGS 1,801,842

PULVERIZER Filed Aug. 8, 1925 3 Sheets-Sheet 3 Z I 1/ 7 a 5 735- I. w v 4? fi 4 Z3 27 I L mb 72 I 25 o o I INVENTOR BY a ATTORNEY Patented Apr. 21, 1931 Iran STATE-5 PATENT OFFICE ARTHUR J. nurses, or srsncnsn, nnw roan, assrsnon To SYRACUSE rULvERIzEs oonrona'rroiv, A conronarrolv or DELAVIARE PULVERIZER i Application filed August 8, 1925. Serial No. 29,053.

This invention relates to pulverizers, and my improvements are of particular utility when, embodied in the construction of amachine, for pulverizing coal tobe used as fuel in furnaces of different kinds, although 1 contemplate the use of my improved machine for general purposes, such as the pulverizing of carbon, clay, and in any other field for which the improvements are adapted by their nature.

An important object of the invention is to combine in a pulverizing machine mechanism for effecting the preliminary grinding of coal by means of a series of sets of swinging hammers arranged in a circleto the centre of which the coal is supplied in convenient sizes (say about one inch), with mechanism for pulverizing the ground coal by means of several rings of teeth arranged co-aXially around the hammers, and co-operating to produce a finer and more homogeneous powder than has been found practicable with other pulverizing machines.

For this purpose, the teeth in each ring are set very close together in order to have as many teeth as possible in a ring, and the rings are also set with the teeth of one ring closely adjacent to the teeth in the neighboring rings, in order to permit the arrangement of several sets of rings in a relatively small space and also to insure the fine pulverizing action which characterizes this machine. I

The teeth are uniformly of keystone cross-. section so that the spaces between the teeth of each ring widen outward radially, and as the material being pulverized is forced outwardly between the teeth by the action of centrifugal force and by the impact of the hammers and of the successive rings of teeth, the particles strike the tapered faces of the teeth and are deflected outward injan approxi mately radial direction which insures effecti ve impact against the teeth of thenext ring, this outward and forward progress continuthroughout. the series of rings. Th first, third and fifth rings of teeth are stationary, and the second and fourth rings revolve therebetween, sothat the particles are delivered from ring toring; with violent impants t a nsure fine pll v rizat on- Another important object of the invention isto combine with this grinding and pulverizmg mechanisms a fan proportioned to draw in and mix with the pulverized coal an equivalent supply of air, i. e., the right amount to burn the coal which the machine is designed to pulverize.

Acognate object is to provide adjustable means to regulate the supply of coal, and means to regulate the supply of air, these regulating means being co-ordinated so that the adjustment of the coal-supplying means efieets automatically a regulation of the air supply in proportion to the amount of coal supplied.

The various features are illustrated and described fully in the accompanying drawings and specification and pointed out in the claims.

In the'drawings, I

Fig. 1 is a view in vertical section of pulverizing apparatus in the construction of which my invention has been embodied.

Fig. 2 is a vertical section on the line II-II of Fig. 1.

Fig. 3 is fragmentary detail view, on an eniarged scale, of a portion of the periphery of the rotor showing the construction and arrangement of the teeth carried thereby.

Fig. i is a similar fragmentary detail view of the corresponding portion of the stator, with several of the teeth carried thereby in position to co-operate with the teeth illustrated inFig. 3. t t

F g. '5 1s a plan vlew of the pulverlzer.

Fig. 6 1s a front elevation thereof.

in the illustrated embodiment, a coal pulverizer is shown comprising a casing designated generally by the reference numeral 1, bolted upon a suitable base 2, serving as a support for the operating parts of the ma chine, including a rotor designated generally by the numeral 3 and provided with a hub 4L mounted to rotate upon ball-bearings 5 carried by a hollow shaft 6 formed upon a disk provided with hammers or beaters ,10, of

which there may be any suitable number, supported in any suitable fashion upon the rotor, and in the instance illustrated there are five sets of these hammers, each set comprising seven hammers or beaters, preferably of the shape illustrated in Figs. 1 and 2, being of generally rectangular eleva ion, with rounded corners 11 and each having apertures 12 to receive a bolt 13 transfixing one complete set of seven of the hammers, and passing through the hub 4 of the rotor and through rings 14 and 15 at the front and rear of the hub respectively.

Bushings 16 and spacing rings 17 are preferably provided to aid in maintaining the hammers 10 in proper assembled relation, and it will be noted that each of the hammers has two of the apertures 12, so that when one end of any hammer becomes worn, it may be turned end for end.

To co-operate with the hammers and initiate pulverization after the operation of grinding the material there is provided an apertured ring which may be of any suitable construction, as for example that illustrated,

comprising a ring grating 19 having bars 20 spaced to form openings 21 (see Fig. 2) these bars being preferably of keystone section, the inclined faces a of neighboring bars being divergent, so that the peripheral openings of the grating are wider than the openings presented nearest to the free ends of the hammers 10, the inner working faces of the bars presenting sharp cutting edges 22 to co-opcrate with the hammers in grinding the coal or other material under treatment.

The ring 19 is preferably supported by an other ring 23, to which it is bolted at 24, the ring 23 being in turn bolted at 25 to the face of a cylindrical casing member 26 which is bolted at 27 upon a casing member 28, the latter being integral with the casing part 1, the parts above mentioned serving with the disk 7 to enclose the rotor.

The ring 23 serves also as a support for a series of annular sets of pulverizing teeth 29 and 30 respectively, which may be formed integrally with a ring 31 bolted at 32 to the ring 23, and projecting therefrom into the path of the material passing from the grate 19.

The teeth 29 and 30 are preferably tapered inwardly from their region of support by the ring 31, having their peripheries 33 approximately parallel with the axis of rotation of the rotor while their inwardly presented faces 34 are respectively inclined at approximately similar angles to said axis, and these sets of teeth are preferably respectively of keystone cross-section like the bars 19, as shown clearly in Fig. 2, with the inclined adjacent faces a of neighboring teeth divergent.

, To co-operate withthe sets of teeth 29 and 30 in pulverizing the coal, I have shown at 35 and 36 similar oppositely extending sets of teeth formed upon a ring 37 bolted at 38 upon the main disk or body part of the rotor 3, which constitutes the inner wall of the grinding chamber.

The sets of teeth 35 and 36 are preferably of the characteristic keystone cross-section already described, the adjacent faces a of neighboring teeth being divergent. The teeth 35 and 36 are also preferably tapered in reverse direction to the sets of teeth 29 and 30, the set of teeth 36 extending between the sets of fixed teeth 29 and 30, while the set of teeth 35 extends between the set of fixed teeth 29 and the peripheries of the bars 20, so that there is a repeated pulverizing action, first between the peripheral cutting edges 39 of the grate bars 20 and the inwardly directed cutting edges 40 of the teeth 35; then between the parallel inclined cutting edges 41 of the teeth 35 and the inwardly directed cutting edges 34 of the fixed teeth 29; then between the inwardly directed cutting edges 42 of the teeth 36 and the edges 33 of the fixed teeth 29; and finally between the inclined cutting edges 43 of the teeth 36 and the inwardly directed inclined cutting edges 34 of .the fixed teeth 30.

The material under treatment is delivered to the center of tne grinding chamber G by a spout- 44 which may receive its supply from any suitable source, being shown as provided with a funnel 45 to which the coal or other material is fed from a hopper 46 over a rotating table 47 from which the material is scraped by a knife 48. The table 47 is rotated in the instance illustrated by means of a shaft 49 mounted in bearings 50 carried by the casing and driven by a pulley 51 which derives its power from a belt 52 passing over an idler 53. i

The course of the material during grinding and pulverizing is indicated by the arrows in Fig. 1, and the pulverized material is delivered into the peripheral chamber 54, and thence to a delivery chamber 55 in which operates a fan formed by vanes 56 secured upon a flange or spider 57 formed as part of the hub 4 of the rotor, and the product is forced out by the fan through a pipe 58 for use as desired. At 59 is shown an air regulator through which air is drawn by the fan in sufficient volume to produce a strong blast. Suitable lubricating means are shown at 60 and the rotor may be rotated at a relatively hi h speed, as for example about 1.400 R. P. M.

An important feature of the invention is the provision of means to regulate the feeding of the coal and the admission of air in such a manner as to co-ordinate the same for securing proper combustion when different amounts of coal are being fed.

The now preferred mechanism for this purpose comprises a controller member which takes the form of a rock-shaft 66 in the inuser-sea stance-illustrated, providedywith a hand? lever 67 and clamping wheel 68; being adapted for adjustment rotatively to vary the respective positions of the knife48 and the air controllen 59; simultaneously, by means of connections comprising an adjustable rod 69leading-from an arm 70 on the rock-shaft to an arm 71 of a bell-crank on the pivot-shaft 72 of the arm 73! carrying the feed-knife d8,v and connections to the shutter comprising a link 7,4 bolted adjustably at 75 to a slotted lever arm, 76' on the rock-shaft and at 77 to laislotted lever arm 7 8 on the shutter 79 ofthe air-controller. 59. By means of the socket-members 80 and. nuts 7 81: on threaded portion 82 of thelink-rods 69 and 74 respectively, their lengthmaybe adjusted. i

The knife 48 is: shown in position to scrape fromthe rotating tablethe maximum amount of coal which themachine is designed to pulverize, and the shutter is shown with its air openings 83 fully open-,to admit the full volume of air required for proper combuse tion of themaximum quantity of pulverized coal delivered by the fan, and. in. the0peration of the controlling mechanism: movement of the lever 67 in the direction of the arrow, Fig; 6 will turn shaft 66and arm 70 counter-clockwise, and by the action of' the rod 69 will turn the bell-crank levers 7173 clockwise and shift thelknife 4:8'outwa-rd so that it will scrapeless coal f'romtherotating table 47. At the same time the aforesaid rotation of the rock-shaft 66: will, by the action of itsarm 76, through the link 74 and shutter-arm 78, turn the shutter 79, closingthe air openings 83', sothat a lesser amount of air is admitted, properly proportioned to effect complete combustion of the pulverized coal] when delivered by the fan.

The casing is preferably made of a size 7 suitable to receive a fan having vanes either larger or smaller than those illustrated at 56, and by a simple substitution ofvanes of the proper size the fan may beadapted to deliverthe desired amount of pulverized coal which may be required by the particular in: stallation; the supply of coal to the pulverizer, and the admixture of air in proper quantities therewith being regulated automatically as above described.

The-controlling shaft 66 may be connected with suitable temperattire-controlled devices located at the point of combustion (not shown) for the purpose of providing for automatic regulation of the amount of fuel and air in accordance with the heatto be deQ veloped, thus maintaining the heat at the desired degree. r

In pulverizing coal it is preferred to sup: ply the hopper 46' with coal 'in approximately one inch size, and after grinding and pulveri-zing the coal emerges in a very finely pulverized condition. o

The, pulverizerabove described is extremely compact and solid in, construction and, powerful in action, being free from destructive vibrations, and access may be had; readily toits parts for repairs and substitution.

By reason, of its compact construction, it may be installed directly adj acent to the apparatus in which the pulverized coal is to be used, avoiding the need for long conduits and for sustaining a very high air pressure. Accordingly its use makes possible the utilization of pulverizedicoal in plants wheresuch, use has not. been found practicable hereto? fore, owing to the size and expense of machinery designed therefor. j v

The particles of coal forced through: the grate 19 strike the sides of the keystone shaped teeth and aredefiectedoutwardin an approximately radial. direction; toward the teeth of the next ring, where the pulveri-zing action is continued, and asthe material is forced progressively through each ring the divergently opposed faces of the keystone teeth similarly act to,a id its forward "progress. This forward passing of thematerial,

and the. close proximityofthe teeth in, the adjacent rings, together with the fact that alternate rings. are stationary while the intervening rings 7 rotate causes violent impacts of the particles and these impacts are so numerous, by reason of; the multiplicity of; closely arranged teeth, that, thecoa-l is P1111 verized to a degree. not deemed practicable heretofore, and is in. a, condition for ready and complete combustion.

Having described: my invention, 1 claim:

1 In a pulverizer, the combination with a series of grinding hammers swinging upon centres spaced radially about a, common axis and adapted torevolvearound: said; a is, of a co-axially' disposed apertured ring sur roundingsaid hammers, and cooperating relatively revoluble annular sets of teeth also disposed about said axis, certain of said sets having multiple teeth arranged: closely ad:

jacent to each other and tothe teeth of adjoiningv sets, said hammers. being adapted to co-operate yieldingly with said apertured ring, to initiate pulverization of the ground material, andto deliver'said material: tolfsai d teeth for further pulverization.

2. In a pulverizer, the combination with a series of hammers swinging upon centres spaced radially about a common axis and adapted to revolve around said axis. acting to grind the material to; be treated, of an apertured ring and annular sets of teeth also disposed around said axis, surrounding said hammers, and co-operatmg relatively revoluble annular sets of teeth projecting between said other sets of teeth, and means to. deliver material in regulated quantities at the central region of said pulverizer for grinding by said hammers and pulverization by said annular sets of teeth respectively, and means to supply equivalent air to said pulverizer, said hammers being adapted to co-operate yieldingly with said apertured ring to initiate pulverization, and also to co-operate with said air to deliver the material. for further pulverization between said relatively revoluble sets of teeth.

3. In a pulverizer, the combination with a series of grinding hammers swinging upon centres spaced radially about a common axis and adapted to revolve around said axis, of annular sets of teeth surrounding said hammers concentrically, and co-operating relatively revoluble annular sets of teeth projecting between said other sets of teeth, and means to deliver material in regulated quantities at the central region of said PLllVSllZGl for grinding by said hammers and pulverization by said annular sets of teeth respectively, and a fan to draw an equivalent sup y of air into said pulverizer, prior to grin rug and pulverization, and deliver the pulverized material mingled therewith for combustion.

4:. A pulverizer comprising av casing; a rotor mounted within said casing; a series of swinging grinding hammers mounted pivotally on said rotor in spaced relation about its axis; an apertured ring and annular sets of teeth mounted on said casing co-axially with said rotor and surrounding the hammers in spaced relation; and co-operating relatively rotatable annular sets of pulverizing teeth mounted upon said rotor, projecting between said casing sets of teeth, each of said sets having multiple teeth arranged closely adjacent to each other and to the teeth of adjoining sets, said hammers being adapted to co-operate yieldingly with said apertured ring to initiate pulverization.

5. A pulverizer comprising a casing; a rotor mounted within said casing; a series of swinging grinding hammers mounted pivotally on said rotor in spaced relation about its axis annular sets of teeth mounted on said casing coaxially with said rotor and surrounding said aXis in radially spaced relation; and co-operating relatively rotatable annular sets of teeth mounted upon said rotor, projecting between said casing sets oi teeth, each of said sets having multiple teeth arranged closely adjacent to each other and to the teeth of adjoining sets, said teeth respec tively being of keystone shape in cross-section so that the neighboring inclined walls of adj acent teeth in a set are divergent and serve to direct outwardly in an approximately radial direction the particles -forced therebetween by the successive grinding and pulverizing impacts.

6. In a pulverizer, a series of concentrically disposed annular sets of teeth; means to cause relative rotation between alternate sets; and means to feed centrally thereto the material to be ground; each of said sets having multiple teeth arranged closely adjacent to each other and to the teeth of adjoining sets, said teeth being respectively of keystone shape in crosssection so that the neighboring inclined walls of adjacent teeth in a set are divergent and serve to direct outwardly in an approximately radial direction the particles i'orced therebetween by the successive pulverizing impacts.

7. A pulverizer characterized by acasing provided with grinding and pulverizing mechanism comprising a series of annular sets or teeth mounted upon said casing, and a rotor having a series of annular sets of teeth arranged in alternate pulverizing relation with said casing-supported sets of teeth, said rotor having also a series of swinging hammers arranged in grinding relation centrally within said sets of teeth, and a fan comprising a set of vanes mounted. on said rotor and proportioned to the amount of material to be treated, said casing being constructed to permit the use of sets of vanes or different sizes in combination rith the same sets of teeth and hammers.

8. A pulverizer characterized by a casing having a centrally arranged hollow shaft, a rotor having an actuating shaft mounted rotatably within said hollow shaft and having a disk arranged to divide said casing into a pulverizing chamber and a delivery cham ber, pulverizing elements mounted respectively on said casing and rotor in said pulverizing chamber, and a fan mounted on said rotor in said delivery chamber.

9. A pulverizer characterized by a casing having a centrally arranged hollow shaft, arotor having an actuating shaft mounted rotatably within said hollow shaft and having); a disk arranged to divide said caslng into a pulverizing chamber and a delivery chamber, pulverizing elements mounted respectively on said casing and rotor in said pulverizing chamber, and fan mounted on said rotor in said delivery chamber, said pulverizing elements comprising a series of annular sets of teeth supported by rings secured removably to said casing, a series of annular sets of teeth secured removably to said rotor in co-operative relation with said casing teeth, and a series of sets of swinging hammers support ed removably upon said rotor centrally in grinding relation with said casing teeth.

10. In a pulverizer, the combination with a series of sets of hammers swinging in multiple upon centres spaced radially about a common axis and adapted to revolve around said axis and grind the material, each hammer being capable of independent swinging movement, of a stationary ring provided with openings and surrounding said hammers in close uxtaposition thereto, and with which said hammers co-operate yieldingly to effect preliminary pulverization of the material, and a series of annular sets of closely arranged teeth revoluble in close juxtaposition relatively to each other and relatively to said ring and to which said partly pulverized material is delivered from said apertured ring for further pulverization, said ring serving to confine the coarser particles of material and thus to divide the operation of grinding and preliminary pulverization from that of fine pulverization.

11. In a pulverizer, the combination with a series of hammers swinging upon centres spaced radially about a common axis and adapted to revolve around said axis and grind the material, of means to feed material to said hammers at the region of said axis, and a series of annular sets of teeth, revoluble relatively to each other, and to which said ground material is delivered from said hammers for pulverization.

12. In a pulverizer, the combination with a series of hammers swinging upon centres space-d radially about a common'axis and arranged to leave the axial region free to receive the material to be treated, said hammers being adapted to revolve around said axis and grind the material, of means to feed material into the axial space confined by said hammers.

13. In a pulverizer, the combination with a casing enclosing a pulverizing chamber, and a rotor comprising a disk constituting one wall of said pulverizing chamber, of a series of members projecting from the face of said disk into said pulverizing chamber to form bearing centres, and a series of hammers swinging upon said centres and spaced radially about the axis of said rotor, leaving the axial region free, said hammers being adapted to revolve with said rotor around said axis and to grind the material, and means comprising a conduit entering said axial space to deliver material radially to said hammers.

14. In a pulverizer characterized by encased revolving grinding and pulverizing mechanism, and by a fan arranged to draw into said mechanism a supply of air; an airregulator; and co-ordinating connections for the purpose set forth further characterized by a controller device including a rock-shaft connected by adjustable links with the airregulator and with a knife acting to scrape the material to be treated from a rotating table fed by a hopper receiving said material from a suitable'supply thereof.

15. A pulverizer characterized by encased revolving grinding and pulverizing mechanism, and by a fan arranged to draw into said mechanism a supply of air; an adjustable shutter arranged in the path of said air-supply, near the axis of revolution of said grinding and pulverizing mechanism; said pulverizer being characterized further by mechanism for feeding a regulated supply of the material to be ground and pulverized, said feeding mechanism comprising a rotatable supply table with a supply hopper and a feeding spout, a pivoted knife to scrape said material from said table into said spout, and a controller rock-shaft connected by adjustable links with said knife and said shutter respectively, and acting when said rockshaft is rotated in one direction to turn said knife on its pivot to scrape an increased supply of material from'said table and to open said shutter to admit a proportionately increased supply of air through said shutter, said rock-shaft acting similarly when rotated in the reverse direction to decrease proportionately the supplies of material and air.

7 In testimony whereof,'I have signed this specification.

ARTHUR J. BRIGGS. 

